Model airplane wheel



April 7, 1953 A. B. MAXAM MODEL AIRPLANE WHEEL Filed May 27, 1948 2 SHEETS--SHEET l INVENTOR. ALLEN B MAX/1M JMQT ATTORNEY April 7, 1953 A. B. MAXAM 2,634,168

MODEL AIRPLANE WHEEL Filed May 27, 1948 2 SHEETS-SHEET 2 H6. 2 tziw,

- INVENTOR. ALLEN B. MXAM ATTORNE Patented Apr. 7, 1953 1 UNITED" STATES PATENT OFFICE MODEL AIRPLANE WHEEL Allen B.-Maxam, Burbank calif.

Application Mayzv, 194s; sell-farm; 29,523

3vGlaims. 1 The invention relatesto wheelsof thetype used for model airplanes: and -the like and has for its object-to provi'de an efiective; efficient and relatively simple: construction for' such a wheel. Itis desired that wheels for model aircraft shallbe very light in weightand yetsturdy enough so that they will notcomeapart when the aircraft is taking off or landing. I'naccordance with: mypresent invention; I provide a construction which fit'sthese needs. "Icarry out my invention by the provision of the Wheel axle within at bushing rotatable about. the. axle,v the axle b eihg lockedfin position: within the; bushing; The bushing is suitably fastened within ithef hub at the: wheel so: that it will not" come off: or? come apart in action. Features- 011 my novel construction relate: to the provision of the hub in two: mating parts held together by the bushing. A related feature: the provision-of a; locking means set withma groove: of the axle"- for lockingthe axle within the" bushing; Y 1 Afnothert feature which: may-be used is. the pro-- vision. of means in association? hub for mounting: a. rubber or rubb'erlike' tire onsthe: hub.- Other featuresi-randmodificationswillibetbetter; understood from the following detailed descrip tionand the accompanying drawings of which:

Fig: 1 illustratestwo wheels of" a: model aircraft:- mounted' infthe'relationl to each: other in: which they are actually used;

Fig. 2 15 'a" side elevation of one: of f the:- wheels lo'oking'from lineL-l of: Fig I Eiez'tisa: cross-section. of one ofitli'e wheels taken at line; 3'3: of: Fig. 2

Eig:- 4; is a; cross-sectionwviewshowing a'1coni-- stmction which 1 is: modified from: that 1 of? Fig. 3 this view: likewise: being" taken at: line 3 -3 of Big: 2

Fig; hisa; cross sectioni view" showing a detail; of. the: axle: locking? constructiom taken at.) line ie i'ofiEigsltgz t Figtsolis-azcross-section view-showinga detail: takematline: li -6 of Rig; 3*; Fig-:97: is: an: endxrelevatiom view. partially in; crossesect-ioml showing;- a:.- modified formof-: hub assembly according) to my; invention;

Eigr-Bl is a side-elevation: taken=at line 8-8 of Fig. 9:4isiatcross-sectioniview of. another modificationeof a hub assembly accordingto my invention; and? Hg:10 is"a cross=section view" showing still another-modification ofhuhassembly according termsinventlozr.

Fig. 1 illustrates a rear-view" of the leftantt right wheels i and 2 of a model aircraft; amt shows the aX1es 3- and-4, respectively, protruding from the hubs 5 and 5 of the wheels. Around the respective hubs are placed tires I and 8 Fig: 3showsone of the wheels 2 in cross-section and illustrates the arrangement of the axle 4 and the hub B, the hub being composed of two parts 9- and [8; which fit together. Part 3* comprises a cylindrical peripheral portion I I Y, with a convent end portion 12' extending: from the inner edge of the: peripheralportion to a hollow cylindrical inner portion I 3". I Part I0 similarly comprises a cylindrical peripheral portion i i", with the convex-1 endpoi tion It extending from the outer edge: of the peripheral portion to the hollow'cylindrical portion 1 I. The inner'cylindrical' portions I3 and; l-T are made with the sameinside and Outside diameters so that they" abut each others as= shown. Cylindrical member I3 is provided with a number'of protruding lugs f8; fo'r exampla two such lugs spaced 180 apart and the other c yli'n drical portion 1 1 is p'rovid'ed with corresponding slots or recesses I 9 into which the lugs fit to preventrelative rotation: betweenthe t'wm mem bers 9 and I0 1 The twohubmembers 9' and: m are secured: in this: mated position by means of abushing having external threads 2-11 which thread intocorrespondinginternal threads of: the cylindrical portion ii the T bushing being threaded into: member H" until the" colla'n 22 oi the bushing: firmlyabuts: the convex portion I l of member 9: To facilitatethethreading'i th'e': head: of the bushing is-pre ferably" fiattened at 2 to: receive alwrencht The-axle 4 fits through-the bushing 20 with a nice fit so: that relative rotationi's permitte be tween the axle and the bushing; Provision made for locking the axle in its position within the bushing; and for'this purpose;., the end -ofi the axle r protrudes beyond the: end ofetheibu'shing arl'd""is 'lock'e'd in this position: by: means of a? locking: ring or oval 2 held 'v'vitl-iin agl wvei or the axle? V I t Fig. 5 isarcross seetioniwewshowmgzirrzdetaili' how' the lockingarrangementfiis assemblem This may; conveniently be done by slipping-i the axle:

I through the bushin 20; before the bushin e'isr assembled?with the hub members SI -ami It Withi theaxle completely within" the bushing; ri'iigI 2 4 of circular shape is slipped: over the end; of; the"; axle to the groove 25- at which position that ring:

is flattened 'to the' oval shape shown 5% This oval shape resultsfrom the: factthat the groove 25 does not pass completely around the axle but is only passed through one side of the axle; so that when the ring 24 is compressed, part of it lies within the groove, and the remainder passes around the periphery of the axle. After this axle and bushing assembly is thus completed. the bushing may then be threaded into the hub members 9 and 10 as described above after which the upper end of the axle may be suitably fastened to the fuselage of the model aircraft. In view of the fact that the oval 24 must thus be passed through the hub members 9 and ID, the largest diameter of the oval should not exceed the internal diameter of the hub threads. 4

Fig. 6 illustrates the use of a continuous rin 24a, which may be inserted in the groove'in circular form and then flattened to the. oval form shown in Fig. 6.

The dimensions and separations of the cylindrical peripheral portions H and 15 of the hub members is such that the tire 8 of the solid or sponge rubber type may readily be fastened in place; For this purpose, the tire is shaped with the usual rounded periphery 28 on which it rolls, and with two cylindrical portions 29 and 3E! corresponding with the cylinders II' and 15. Between the cylindrical portions 29 and 30 there is provided an inwardly protruding annular bulge 3 lwhich fits snugly between the cylindrical members H and to keep the tir from coming off the hub. The tire thus shaped may be assembled on the hub members when the hub members are fitted together by the bushing 20.

Fig. 4 shows amodified form of the hub assembly arrangement. ,In this embodiment, the two opposite hub members 32 and 33 are different from the hub members 9 and In of Fig. 3. Hub member 32 is in the shape of a convex member having centrally through it a hole large enough so that bushing 34 may pass through it. The other hub member 33 is provided with a convex portion 35 similar to hub member 32 and is provided with a cylindrical portion 36 which protrudes inwardly to abut member 32. The cylinder 36 is internally threaded to thread with the threads 31 of bushing 34, which thus screws into cylinder 35 until the collar 38 abuts hub member 32. The axle is locked within the bushing 34 by the groove 25 and flattened ring or Oval 24, the same as in the embodiment in Fig. 3.

- .The tire 39 differs from that of Fig. 3 in that itis shown of the hollow type. It is fitted to the periphery of the convex hub members 42 and 45, by means of peripheral shoulders 48 and 4|. A spacing ring 42 holds the inner portion of the tire spread its proper distance by fitting into annular grooves 43 and 44, formed in the tire. Preferably, a number of holes 45 are placed through the ring to make it lighter.

Figs. '7 and 8 illustrate a modification of the hub assembly which may be especially useful for making hubs of plastic material in molds. The two hubmembers each have the outer peripheral cylindrical portions 48 and 49, respectively, and the convex portions 50 and 5| extending across the. peripheries. Each of the hub members, furthermore, is provided with the inner cylindrical portions 52 and 53 through which the axle protrudes; and the member 52 has the lugs 54 and the member 53 has the corresponding slots 55. The length of cylindrical portion 52 is substantially shorter than the length of cylindrical member 53, in consequence of which member 52 needs no reinforcement. Member 53, however, is provided with a number of reinforcing vanes 56. The

cylindrical member 53 is provided with inner thread 51 to receive the bushing and axle assembly as described in the preceding embodiment and the compartment 58 is provided to allow room for the locking ring assembly. The tire may be fitted to this embodiment in the same way as in the embodiment of Fig. 3.

Fig. 9 shows a further modification which is especially adapted for use with a hub mad of wood. In this embodiment, the hub 59 is a unitary solid construction provided with a'central bore terminating with the recess 60 and the bore is internally threaded at 6| to receive the threads of bushing 62 which is threaded into it up to the collar 63. The axle is held through the bushin in the same manner as in the preceding embodiments by means of the groove 25 and flattened ring 24. The tire 21 may be similar to the same numbered tire in Fig. 3.

Fig. 10 shows a further modification in which the hub member 64 is also of a solid unitary construction provided with the central bor 55 to receive the axle assembly. There is provided an additional bore 65 extending a short distance onwardly from the end of bore 65 and large enough in diameter to receive the end of axle 4. Th inner end of axle 4 is rotatable within bushing 51 which is threaded by threads 68 within hub 64 until the collar 69 abuts the exterior of the hub. A suitable locking member 70 is provided to lock the axle within the bushing 61; and this locking arrangement may be the same groove and flattened ring arrangement as in the precedin embodiments. The tire ll may have its internal periphery shaped to fit the, concave surface '12 of the hub. 1

It will be recognized that by my invention, I have provided a simple and eflicient assembly for a model aircraft wheel which is sturdy in construction and light in weight. Furthermore, the arrangement of the bushing and axle locking arrangement within the hub is applicable to various kinds of material such as li htweight metal, plastics, wood, or other suitable materials. My invention is not to be construed as limited to the particular embodiments illustrated in the drawings and described in the description, which are given by way of illustration rather than of limitation, and the invention is not limited. except in accordance with the scope of the appended claims.

I claim: 7

l. A wheel assembly for model airplanes comprising a hub, a bore axially through the hub extending from one side thereof but not to the other side, an additional bore of smaller diameter than the first-mentioned bore extending axially beyond the first-mentioned bore, a bushing threaded into the first-mentionedbore from the open end thereof, and leaving a space between the inner end of the bushin and the inner end of the first-mentioned bore, an axle through the bushing and having its end inserted within the second bore, the end of the second bore acting as a stop for the end of the axle, and alocking means attached to the axle for preventing .withdrawalof the axle through the bushing, said locking means comprising a groove at a side of the axle and a continuous ovalmember around the axle and passing through the groove.

2. A wheel assembly for model airplanes com--. prising a hub, a bore axially through the hub extendin from one side but not to the other side of the hub, an additional bore of smaller diameter than the first-mentioned bore extending; axially 5 beyond the first mentioned bore, a bushing threaded into the first-mentioned bore from the open end thereof, and leaving a space between the inner end of the bushing and the inner end of the first-mentioned bore, an axle through the bushing having its end inserted into the second bore, the end of said second borebeing a stop for the end of the axle, and a locking means comprising a non-resilient oval extending substantially around the axle and fastened to the axle 1 within said space, for preventing withdrawal of the axle through the bushing.

3. A wheel assembly according to claim 2 in which the axle is provided with a groove at only REFERENCES CITED The following references are of record in the file of this patent:

5 UNITED STATES PATENTS Number Name Date 840,399 Taylor Jan. 1, 1907 904,112 Bastel Nov. 17, 1908 1,911,447 Heuer May 30, 1933 0 2,456,355 Aber Dec.14,1948 2,540,034 Maxam Jan. 30, 1951 one side thereof and the oval passes through the 5 roove.

ALLEN B. MAXAM. 

